This invention relates to conveyors, and more particularly to a number of features in a conveyor which facilitate manufacture, assembly, operation and maintenance of a conveyor.
The present invention contemplates a number of improvements to a conveyor construction, such as that generally disclosed in Dorner et al U.S. Pat. No. 5,174,435, the disclosure of which is hereby incorporated by reference. The '435 patent generally discloses a conveyor construction including a frame and a tensioning section mounted for movement relative to the frame. The tensioning section includes a spindle about which a conveyor belt is trained, and movement of the tensioning section functions to control the tension of the belt. The tensioning section is extended and retracted in response to rotation of a drive pinion rotatably mounted to the frame. The frame includes a channel or slot on each side, and slide bars are located within each slot for longitudinal movement therewithin. The slide bars are interconnected with the tensioning section via an outer plate and one or more threaded screws which extend through openings formed in the outer plate and into threaded engagement with threaded openings formed in the slide bars. When a desired position of the tensioning mechanism has been attained by rotation of the drive pinion, the screws are tightened so as to clamp the portions of the frame adjacent the slot between the outer plate and the slide bars. In this arrangement, the tensioning section is locked in position separate from the drive pinion which functions to provide movement of the tensioning section. In addition, the conveyor disclosed in the '435 patent contemplates a spindle which extends the full width of the belt. Cavities are formed in the ends of the spindle, and a bearing assembly is mounted within each cavity. A collar extends into the cavity and into engagement with the bearing assembly. The collar includes an outer end which is mounted to the side plate for rotatably mounting the spindle to and between the side plates. This construction is generally satisfactory, but can present problems in a wash-down application and presents the possibility that water can make its way into the bearing assembly from the outside of the conveyor.
It is an object of the present invention to provide an improved and simplified conveyor construction providing enhancements in the components, assembly, operation and maintenance of the conveyor construction. Another object of the invention is to provide a conveyor construction in which the tensioning section can be locked in position utilizing a single-point locking mechanism Yet another object of the invention is to provide such a locking mechanism which is operable on the drive pinion, which functions to move the tensioning section relative to the frame. A still further object of the invention is to provide a conveyor construction in which the belt is engaged with the frame between the drive spindle and the idler spindle, to prevent skewing of the belt. A still further object of the invention is to provide a conveyor construction providing an improved structure for engaging the drive pinion with the tensioning section. Yet another object of the invention is to provide a conveyor construction which is capable of use in a wash-down environment by preventing ingress of water into the spindle bearing cavity. Yet another object of the invention is to provide a simplified conveyor frame construction facilitating attachment of conveyor accessories to the frame.
In accordance with one aspect of the invention, a conveyor construction includes a frame, a pair of spindles mounted to the frame and a belt trained about the spindles. An upper support member is associated with the frame and located between the spindles. The upper support member is disposed below the belt, so as to support the belt between the spindles. Mating engagement structure is interposed between the belt, the spindles and the upper support member for preventing lateral movement of the belt relative to the spindles and relative to the frame between the spindles. In this manner, the belt is maintained in a tracked relationship relative to the spindles and to the frame, to prevent skewing of the belt or other lateral movement of the belt. Preferably, the engagement structure is in the form of a rib extending from the underside of the belt, which is received within a longitudinal groove formed in the upper support member within which the rib is received when the belt is engaged with the upper support member. Each spindle includes a groove in alignment with the groove in the upper support member for receiving the rib. The upper support member defines a first end and a second end, and the groove preferably extends the full length of the upper support member between its first and second ends.
In accordance with another aspect of the invention, a conveyor construction includes a frame having a pair of side members, in combination with a belt and a belt tensioning mechanism movably mounted to the frame and including a spindle engageable with the belt. A pair of side members are located one adjacent each frame side member, and a drive member is rotatably mounted to the frame. This aspect of the invention contemplates an improvement in the form of engagement structure provided on both of the side plate members. The drive member is engaged with the engagement structure so as to effect movement of the belt tensioning mechanism relative to the frame upon rotation of the drive member. The drive member is preferably in the form of a rotatable drive pinion having a series of outwardly extending gear teeth, and the side plate member engagement structure is preferably in the form of a series of gear teeth provided on the side plate member and engageable with the drive pinion gear teeth. The side plate member gear teeth cooperate to define an axially extending gear rack which extends along an axis substantially parallel to the direction of movement of the belt tensioning mechanism relative to the frame. Each side plate member preferably includes an axially extending slot located adjacent the gear rack defined by the series of spaced gear teeth. The drive pinion is mounted to the frame side member via a pinion mounting member or carrier, which extends through the side plate member slot and which is interconnected with the frame side member. The pinion mounting member or carrier includes an inner pinion mounting section for rotatably supporting the pinion, and an outer frame connection section extending from the pinion mounting section and disposed within the side plate member slot and engaged with the frame side member. The side plate member gear teeth are preferably formed integrally with the side plate member. This arrangement provides positive engagement of the side plate members with the drive pinion to ensure that the side plate members are simultaneously and synchronously advanced and retracted upon rotation of the drive pinion, to maintain constant tension on the belt throughout the width of the belt.
Another aspect of the invention contemplates a spindle mounting arrangement for a conveyor construction including a belt and at least one spindle about which the belt is trained. The spindle mounting arrangement includes a spindle mounting member having a cavity defined at least in part by an upper wall and a side wall. The cavity includes an inwardly facing opening, and a bearing arrangement is disposed within the cavity for rotatably mounting the spindle to the spindle mounting member. The cavity opening faces the spindle, and the mounting member upper wall and side wall are configured so as to enclose the cavity from the exterior of the mounting member. The spindle includes a belt engaging surface, and the upper wall and side wall of the spindle mounting member terminate in an inner edge at least in part defining the opening. The inner edge is located adjacent the belt engaging surface of the spindle, and the belt is in engagement with the belt engaging surface and overlies the upper wall, the side wall and the inner edge. This arrangement defines a space between the inner edge and the belt engaging surface, and the belt overlies the space. The belt thus seals the space between the belt engaging surface of the spindle and the inner edge defined by the mounting member side wall and end wall, so as to prevent ingress of water into the space and thus prevent water from coming into contact with the bearing arrangement. The spindle preferably includes a shaft extending outwardly from a portion of the spindle defining a belt engaging surface, and the shaft defines an axis of rotation about which the spindle is rotatable. The spindle shaft is engaged with the bearing arrangement to facilitate rotation of the spindle relative to the spindle mounting member.
Yet another aspect of the invention contemplates an improvement in a conveyor construction in which a drive member is rotatably mounted to the frame and drivingly engaged with the tensioning section of a conveyor for imparting longitudinal movement of the tensioning section relative to the frame upon rotation of the drive member. The improvement is in the form of a locking member interconnected with the drive member for selectively preventing rotation of the drive member so as to selectively fix the position of the tensioning section relative to the frame. The locking member functions to frictionally engage the drive member with the frame for selectively preventing rotation of the drive member. The locking member is preferably in the form of a threaded member in threaded engagement with the drive member and including a head located adjacent the frame. An engagement surface is associated with the frame and is located adjacent an engagement surface defined by the drive member. Rotation of the threaded locking member functions to engage the head with the frame to thereby draw the drive member engagement surface into frictional engagement with the frame engagement surface to prevent rotation of the drive member. The drive member preferably defines a pair of spaced ends, and the locking member is engaged with a first one of the spaced ends. A drive actuator is interconnected with a second one of the spaced ends of the drive member, for selectively imparting rotation to the drive member. The drive actuator preferably includes an actuator member drivingly engaged with the drive member and a manually operable handle engaged with the actuator member. The actuator handle is located adjacent a first side defined by the frame. The locking member includes a threaded member threadedly engaged with the drive member and a manually operable locking handle located adjacent a second side defined by the frame opposite the first side. In a preferred form, each end of the drive member is rotatably supported by a drive member carrier fixed to the frame, as summarized previously.
A still further aspect of the invention contemplates an improvement to a conveyor construction as summarized above, in the form of a rotation or actuator arrangement interconnected with the drive member for imparting rotation to the drive member, and a locking device separate from the rotation arrangement and operable on the drive member for selectively locking the drive member against rotation to thereby fix the longitudinal position of the tensioning section relative to the frame. The rotation arrangement includes an axially extending drive member actuator which extends along the axis of rotation of the drive member, and the locking device includes a threaded locking member threadedly engaged with the drive member. The locking member extends along a longitudinal axis coincident with that of the drive member actuator. The drive member preferably defines a pair of spaced ends, and the drive member actuator is engaged with one end of the drive member and the threaded locking member is engaged with the other end of the drive member. A handle is preferably interconnected with the drive member actuator and is located adjacent one side of the frame, and a locking handle is located adjacent an opposite side of the frame for selectively imparting rotation to the locking member. The drive member is preferably mounted to the frame via a pair of spaced carrier members, as summarized previously.
A still further object of the invention contemplates an accessory mounting arrangement for a conveyor including a frame having at least one side wall defining a lower edge, and at least one spindle mounted to the frame and a belt engaged with the spindle. The accessory mounting arrangement includes a clip member having a pair of spaced walls located on opposite sides of the frame side wall. A conveyor accessory is engageable with the clip member. Engagement structure is associated with the clip member and with the frame side wall adjacent the lower edge. The engagement structure provides movement of the clip member longitudinally along the frame side wall and provides engagement of the clip member with the frame side wall against exertion of a transverse pull-off force away from the frame side wall. A clamping member is engageable with the spaced walls of the clip member for drawing the clip member walls together to clamp the frame side wall therebetween. In this manner, the position of the clip member relative to the frame is selectively fixed, so as to mount an accessory in a predetermined position on the frame. The engagement structure is preferably in the form of a lower end portion of the frame being laterally offset from an upper portion of the frame, in combination with a transverse connector section extending between the upper and lower frame portions. At least one of the clip walls defines a lip which extends transversely and into engagement with the transverse connector structure defined by the frame. The clamping member is preferably in the form of a threaded member which is threadedly engaged with one of the clip member walls and which includes a head engageable with the other of the clip member walls. Advancing the threaded member functions to draw the clip member walls together so as to clamp the frame lower end portion therebetween. An accessory for mounting to a conveyor includes a mounting section having an opening through which the threaded member extends, such that the head of the threaded member is engageable with the accessory mounting structure. The threaded member is preferably located below the lower edge of the frame. The transverse connector section of the frame is in the form of an angled wall section which extends between and interconnects the lower end of the upper wall section and the upper end of the lower wall section.
The various aspects of the invention may be used separately from each other, and each serves individually to provide an enhancement to a conveyor structure. The various aspects of the invention can also be employed in combination to provide significant overall enhancements to a conveyor construction, as will be appreciated.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.